Monitor Description

If there are deposits in the throttle valve, a decrease in the ISC flow rate may cause engine stall or unstable idling. Therefore, the necessary ISC flow rate for idling is maintained using the ISC learned value and feedback. The ECM stores this DTC if the ISC learned value approaches its limit. The ECM begins monitoring for the DTC detection conditions when the following preconditions are met:

• 1) The mass air flow meter sub-assembly is normal.
• 2) Atmospheric pressure is 85 kPa(abs) [637.5 mmHg(abs)] or higher.
• 3) The vehicle has been driven at a speed of 30 km/h (18.6 mph) or more at least once.
• 4) The engine coolant temperature is 45°C (113°F) or less at engine start, the engine is warmed up and conditions for ISC learning are met, or the engine switch has been turned on (IG) (include engine running) for 1 hour or more, the engine is warmed up and conditions for ISC learning are met.